No field is completely uniform. Differences in soil, crop development and weed pressure can require a different treatment from one zone to another. A spraying prescription map defines in advance which site-specific treatment the sprayer applies at each location. This gives every zone the intended application rate and reduces the risk of over- and underapplication.
A spraying prescription map is a digital map that specifies the required treatment for each location in a field. Depending on the application, the map can vary the rate by zone or switch individual nozzles on and off. It is created in advance from available field data and uploaded to the sprayer’s control terminal.
During spraying, a GNSS receiver, such as GPS, determines the machine’s position on Earth from satellite signals and correction data. The controller matches that position to the prescription map and adjusts the application automatically. As a result, each part of the field receives the prescribed site-specific treatment.
Prescription maps can be created from satellite imagery, drone imagery, soil maps, yield maps or crop scans. These data sources show field variability and provide the basis for the treatment assigned to each zone.
A prescription map is most useful when conditions vary within a field. Instead of using one setting across the entire field, you define what each zone needs to create the intended conditions for the crop. Applying the right amount in the right place reduces the risk of using too little or too much product.
The main benefits include:
This matches the treatment more closely to field conditions and can reduce overall product use.
A prescription map and real-time detection are different technologies, but they can complement each other. The map controls a planned treatment based on data collected earlier. The sensors in WEED-IT precision spraying assess the actual field situation while the sprayer is moving.
With WEED-IT, you can execute a spot-spraying prescription map while detection also responds to weeds that emerged after the map was created. The prescription map covers the known locations, while real-time detection includes newly emerged weeds. This means you do not have to choose between map-based spraying and sensor detection.
For selective weed control, this approach can reduce herbicide use by up to 95%, depending on weed pressure and field conditions.
To execute a prescription map at a high spatial resolution, map processing and nozzle control must operate at the same level of detail. Within the WEED-IT system, these functions work together. Combined with WEED-IT DASH, WEED-IT AQRATE can execute prescription maps at a detail level of 25 x 25 cm.
PWFM technology controls the output of each nozzle while spray pressure and droplet size remain stable. The system compensates for changes in driving speed and for turns. This reduces the risk of over- and underapplication and applies the rate specified for each zone in the prescription map.
A practical example in the Netherlands is the installation at Speelman in Eerste Exloërmond. A 45-metre Amazone UX 7601 sprayer was equipped with WEED-IT AQRATE. Prescription-map control is combined with variable output per nozzle and automatic compensation for speed changes and turns. This keeps the treatment of each zone under control while maintaining a high field capacity.
Read more in the field example at Speelman.
A prescription map provides a clear starting point, but field conditions can change between data collection and spraying. By combining map-based control with real-time detection, known locations can be treated while newly emerged weeds are identified in the same pass.
For broadcast applications, WEED-IT cover mode can apply a fixed or variable rate with individual nozzle control. For selective weed control, real-time detection adds current field information. Together, prescription maps, PWFM and detection support one spraying strategy that can be adapted to the application.
